Difference Between Pinocytosis and Receptor-Mediated Endocytosis

Pinocytosis and Receptor-Mediated Endocytosis

Summary: Difference Between Pinocytosis and Receptor-Mediated Endocytosis is that Pinocytosis (“cell drinking,” from Gr. pinein, to drink cyto, cell) is nonspecific uptake of small droplets of extracellular fluid. While Receptor-mediated endocytosis involves a specific receptor protein on the plasma membrane that “recognizes” an extracellular molecule and binds with it.

Pinocytosis

Pinocytosis (“cell drinking,” from Gr. pinein, to drink cyto, cell) is nonspecific uptake of small droplets of extracellular fluid.Any small solid dissolved in the fluid is also taken into the cell. Pinocytosis occurs when a small portion of the plasma membrane indents (invaginates). The open end of the invagination seals itself off, forming a small vesicle. This tiny vesicle detaches from the plasma membrane and moves into the cytoplasm.

Receptor-Mediated Endocytosis

Receptor-mediated endocytosis involves a specific receptor protein on the plasma membrane that “recognizes” an extracellular molecule and binds with it.This reaction somehow stimulates the membrane to indent and create a vesicle containing the selected molecule. A variety of important molecules (such as cholesterol) are brought into cells in this manner.